Re: [PATCH v5 2/2] spi/pl022: Add devicetree support

[Alexandre Pereira da Silva]

On Tue, Aug 21, 2012 at 1:01 PM, Roland Stigge <stigge@xxxxxxxxx> wrote:
> This patch adds device tree support to the spi-pl022 driver.
>
> Based on the initial patch by Alexandre Pereira da Silva <aletes.xgr@xxxxxxxxx>
>
> Signed-off-by: Roland Stigge <stigge@xxxxxxxxx>

Acked-By: Alexandre Pereira da Silva <aletes.xgr@xxxxxxxxx>

> ---
>
>  Documentation/devicetree/bindings/spi/spi_pl022.txt |   15 +++
>  drivers/spi/spi-pl022.c                             |   79 +++++++++++++++++---
>  2 files changed, 85 insertions(+), 9 deletions(-)
>
> --- linux-2.6.orig/Documentation/devicetree/bindings/spi/spi_pl022.txt
> +++ linux-2.6/Documentation/devicetree/bindings/spi/spi_pl022.txt
> @@ -6,7 +6,22 @@ Required properties:
>  - interrupts : Should contain SPI controller interrupt
>
>  Optional properties:
> +- num-cs : total number of chipselects
>  - cs-gpios : should specify GPIOs used for chipselects.
>    The gpios will be referred to as reg = <index> in the SPI child nodes.
>    If unspecified, a single SPI device without a chip select can be used.
>
> +SPI slave nodes must be children of the SPI master node and can
> +contain the following properties.
> +
> +- pl022,interface : interface type:
> +       0: SPI
> +       1: Texas Instruments Synchronous Serial Frame Format
> +       2: Microwire (Half Duplex)
> +- pl022,com-mode : polling, interrupt or dma
> +- pl022,rx-level-trig : Rx FIFO watermark level
> +- pl022,tx-level-trig : Tx FIFO watermark level
> +- pl022,ctrl-len : Microwire interface: Control length
> +- pl022,wait-state : Microwire interface: Wait state
> +- pl022,duplex : Microwire interface: Full/Half duplex
> +
> --- linux-2.6.orig/drivers/spi/spi-pl022.c
> +++ linux-2.6/drivers/spi/spi-pl022.c
> @@ -41,6 +41,7 @@
>  #include <linux/scatterlist.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/gpio.h>
> +#include <linux/of_gpio.h>
>
>  /*
>   * This macro is used to define some register default values.
> @@ -1778,12 +1779,14 @@ static const struct pl022_config_chip pl
>  static int pl022_setup(struct spi_device *spi)
>  {
>         struct pl022_config_chip const *chip_info;
> +       struct pl022_config_chip chip_info_dt;
>         struct chip_data *chip;
>         struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
>         int status = 0;
>         struct pl022 *pl022 = spi_master_get_devdata(spi->master);
>         unsigned int bits = spi->bits_per_word;
>         u32 tmp;
> +       struct device_node *np = spi->dev.of_node;
>
>         if (!spi->max_speed_hz)
>                 return -EINVAL;
> @@ -1806,10 +1809,32 @@ static int pl022_setup(struct spi_device
>         chip_info = spi->controller_data;
>
>         if (chip_info == NULL) {
> -               chip_info = &pl022_default_chip_info;
> -               /* spi_board_info.controller_data not is supplied */
> -               dev_dbg(&spi->dev,
> -                       "using default controller_data settings\n");
> +               if (np) {
> +                       chip_info_dt = pl022_default_chip_info;
> +
> +                       chip_info_dt.hierarchy = SSP_MASTER;
> +                       of_property_read_u32(np, "pl022,interface",
> +                               &chip_info_dt.iface);
> +                       of_property_read_u32(np, "pl022,com-mode",
> +                               &chip_info_dt.com_mode);
> +                       of_property_read_u32(np, "pl022,rx-level-trig",
> +                               &chip_info_dt.rx_lev_trig);
> +                       of_property_read_u32(np, "pl022,tx-level-trig",
> +                               &chip_info_dt.tx_lev_trig);
> +                       of_property_read_u32(np, "pl022,ctrl-len",
> +                               &chip_info_dt.ctrl_len);
> +                       of_property_read_u32(np, "pl022,wait-state",
> +                               &chip_info_dt.wait_state);
> +                       of_property_read_u32(np, "pl022,duplex",
> +                               &chip_info_dt.duplex);
> +
> +                       chip_info = &chip_info_dt;
> +               } else {
> +                       chip_info = &pl022_default_chip_info;
> +                       /* spi_board_info.controller_data not is supplied */
> +                       dev_dbg(&spi->dev,
> +                               "using default controller_data settings\n");
> +               }
>         } else
>                 dev_dbg(&spi->dev,
>                         "using user supplied controller_data settings\n");
> @@ -2006,7 +2031,8 @@ pl022_probe(struct amba_device *adev, co
>         struct pl022_ssp_controller *platform_info = adev->dev.platform_data;
>         struct spi_master *master;
>         struct pl022 *pl022 = NULL;     /*Data for this driver */
> -       int status = 0, i;
> +       struct device_node *np = adev->dev.of_node;
> +       int status = 0, i, num_cs;
>
>         dev_info(&adev->dev,
>                  "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
> @@ -2016,9 +2042,19 @@ pl022_probe(struct amba_device *adev, co
>                 goto err_no_pdata;
>         }
>
> +       if (platform_info->num_chipselect) {
> +               num_cs = platform_info->num_chipselect;
> +       } else if (IS_ENABLED(CONFIG_OF)) {
> +               of_property_read_u32(np, "num-cs", &num_cs);
> +       } else {
> +               dev_err(&adev->dev, "probe: no chip select defined\n");
> +               status = -ENODEV;
> +               goto err_no_pdata;
> +       }
> +
>         /* Allocate master with space for data */
>         master = spi_alloc_master(dev, sizeof(struct pl022) + sizeof(int) *
> -                                 platform_info->num_chipselect);
> +                                 num_cs);
>         if (master == NULL) {
>                 dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
>                 status = -ENOMEM;
> @@ -2037,17 +2073,41 @@ pl022_probe(struct amba_device *adev, co
>          * on this board
>          */
>         master->bus_num = platform_info->bus_id;
> -       master->num_chipselect = platform_info->num_chipselect;
> +       master->num_chipselect = num_cs;
>         master->cleanup = pl022_cleanup;
>         master->setup = pl022_setup;
>         master->prepare_transfer_hardware = pl022_prepare_transfer_hardware;
>         master->transfer_one_message = pl022_transfer_one_message;
>         master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
>         master->rt = platform_info->rt;
> +       master->dev.of_node = dev->of_node;
>
> -       if (platform_info->num_chipselect && platform_info->chipselects)
> -               for (i = 0; i < platform_info->num_chipselect; i++)
> +       if (platform_info->num_chipselect && platform_info->chipselects) {
> +               for (i = 0; i < num_cs; i++)
>                         pl022->chipselect[i] = platform_info->chipselects[i];
> +       } else if (IS_ENABLED(CONFIG_OF)) {
> +               for (i = 0; i < num_cs; i++) {
> +                       int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
> +
> +                       if (cs_gpio == -EPROBE_DEFER) {
> +                               status = -EPROBE_DEFER;
> +                               goto err_no_gpio;
> +                       }
> +
> +                       pl022->chipselect[i] = cs_gpio;
> +
> +                       if (gpio_is_valid(cs_gpio)) {
> +                               if (gpio_request(cs_gpio, "ssp-pl022"))
> +                                       dev_err(&adev->dev,
> +                                               "could not request %d gpio\n",
> +                                               cs_gpio);
> +                               else if (gpio_direction_output(cs_gpio, 1))
> +                                       dev_err(&adev->dev,
> +                                               "could set gpio %d as output\n",
> +                                               cs_gpio);
> +                       }
> +               }
> +       }
>
>         /*
>          * Supports mode 0-3, loopback, and active low CS. Transfers are
> @@ -2157,6 +2217,7 @@ pl022_probe(struct amba_device *adev, co
>   err_no_ioremap:
>         amba_release_regions(adev);
>   err_no_ioregion:
> + err_no_gpio:
>         spi_master_put(master);
>   err_no_master:
>   err_no_pdata:
--
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